Crosslinkable elastomer composition and fluororubber molded article

Abstract

A crosslinkable elastomer composition including a crosslinkable elastomer and a surface-oxidized non-oxide ceramic. Also disclosed is a fluoroelastomer molded article having a weight reduction percentage of 2.5% by mass or less and an amount of particles generated of 0.05% by mass or less after O2 plasma irradiation, a weight reduction percentage of 1.8% by mass or less, an amount of particles generated of 0.05% by mass or less after NF3 plasma irradiation, and a compression set of 50% or less after aging at 300° C. for 70 hours.

The invention claimed is: 
     
       1. A crosslinkable elastomer composition comprising a crosslinkable elastomer and a surface-oxidized non-oxide ceramic filler,
 wherein a peak assigned to an oxide and a peak assigned to a non-oxide give a ratio (oxide:non-oxide) of 3:7 to 6:4 in ESCA measurement of surface-oxidized non-oxide ceramic filler, 
 wherein the non-oxide ceramic filler has an average particle size of 0.1 μm or smaller. 
 
     
     
       2. The crosslinkable elastomer composition according to  claim 1 ,
 wherein the non-oxide ceramic filler is silicon carbide. 
 
     
     
       3. The crosslinkable elastomer composition according to  claim 1 ,
 wherein the crosslinkable elastomer is a copolymer of tetrafluoroethylene and perfluoro(alkyl vinyl ether). 
 
     
     
       4. A fluoroelastomer molded article produced from the crosslinkable elastomer composition according to  claim 1 , having
 a weight reduction percentage of 2.5% by mass or less and an amount of particles generated of 0.05% by mass or less after 02 plasma irradiation under predetermined conditions, 
 a weight reduction percentage of 1.8% by mass or less and an amount of particles generated of 0.05% by mass or less after NF 3  plasma irradiation under the predetermined conditions, and 
 a compression set of 50% or less after aging at 300° C. for 70 hours, 
 wherein the predetermined conditions are: 
 sample: O-ring (AS-568A-214), 
 
       measurement details: 
       (1) O 2  plasma
 plasma irradiation device: ICP high-density plasma device, 
 
       irradiation conditions,
 gas flow rate: 16 SCCM, 
 RF output: 400 Wh 
 pressure: 2.66 Pa, 
 etching time: 30 minutes, 
 temperature: 100° C., 
 these conditions allowing a perfluoroelastomer (non-filler) to be etched at a rate of 12000 Å/min, 
 
       (2) NF 3  plasma
 plasma irradiation device: ICP high-density plasma device, 
 
       irradiation conditions,
 gas flow rate: 16 SCCM, 
 RF output: 400 Wh, 
 pressure: 10 Pa, 
 etching time: 4 hours, 
 temperature: 200° C., and 
 these conditions allowing a thermally oxidized silicon (SiO 2 ) wafer film to be etched at a rate of 90 Å/min.